... Denitrification transforms nitrogen applied as fertilizer and emits N₂O, which is a potent greenhouse gas. Very little is known about the identities of abundant and active denitrifiers in agricultural soils. We coupled DNA stable‐isotope probing (DNA‐SIP) with flow‐through reactors (FTRs) to detect active agricultural soil denitrifiers. The FTRs were incubated with nitrate and ¹³C₆‐glucose under a ...

... Herbaspirillum seropedicae is an associative, endophytic non‐nodulating diazotrophic bacterium that colonises several grasses. An ORF encoding a LysR‐type transcriptional regulator, very similar to NodD proteins of rhizobia, was identified in its genome. This nodD‐like gene, named fdeR, is divergently transcribed from an operon encoding enzymes involved in flavonoid degradation (fde operon). Apige ...

... Cyanobacteria, the only prokaryotes capable of oxygenic photosynthesis, play a major role in carbon, nitrogen and phosphorus global cycling. Under conditions of increased P availability and nutrient loading, some cyanobacteria are capable of blooming, rapidly multiplying and possibly altering the ecological structure of the ecosystem. Because of their ability of using non‐conventional P sources, t ...

... This work elucidates spatio‐temporal aspects of the biogeochemical transformation of copper mobilized from malachite (Cu₂(CO₃)(OH)₂) and bioaccumulated within Aspergillus niger colonies when grown on different inorganic nitrogen sources. It was shown that the use of either ammonium or nitrate determined how copper was distributed within the colony and its microenvironment and the copper oxidation ...

... The anaerobic, mesophilic and moderately halophilic strain L21‐Spi‐D4ᵀ was recently isolated from the suboxic zone of a hypersaline cyanobacterial mat using protein‐rich extracts of Arthrospira (formerly Spirulina) platensis as substrate. Phylogenetic analyses based on 16S rRNA genes indicated an affiliation of the novel strain with the Bacteroidetes clade MgMjR‐022, which is widely distributed an ...

... Human activities are causing a global proliferation of cyanobacterial harmful algal blooms (CHABs), yet we have limited understanding of how these events affect freshwater bacterial communities. Using weekly data from western Lake Erie in 2014, we investigated how the cyanobacterial community varied over space and time, and whether the bloom affected non‐cyanobacterial (nc‐bacterial) diversity and ...

... Having the right coping strategy for changes in osmolarity or desiccation is essential for the survival of every cell. So far, nothing is known about compatible solutes and the salt adaptation of the marine Rhodobacteraceae. The family member Dinoroseobacter shibae DFL12ᵀ is shown here to form the compatible solutes α‐glucosylglycerol (GG) and α‐glucosylglycerate (GGA). To our knowledge, this is t ...

... The ecological relevance and factors shaping dynamics of Limnohabitans sp. have been largely studied by fluorescence in situ hybridization with a 16S rRNA probe targeting the R‐BT group (lineages LimBCDE), but not lineage LimA. Consequently, ecology and distribution of LimA remained unknown. We developed a double hybridization strategy using a novel 23S rRNA probe specifically targeting LimA and L ...

... Ectoine and 5‐hydroxyectoine are widely synthesized microbial osmostress protectants. They are also versatile nutrients but their catabolism and the genetic regulation of the corresponding genes are incompletely understood. Using the marine bacterium Ruegeria pomeroyi DSS‐3, we investigated the utilization of ectoines and propose a seven steps comprising catabolic route that entails an initial con ...

... Gammaproteobacterial Reinekea spp. were detected during North Sea spring algae blooms in the years 2009‐2012, with relative abundances of up to 16% in the bacterioplankton. Here, we explore the ecophysiology of ‘R. forsetii' strain Hel1_31_D35 that was isolated during the 2010 spring bloom using (i) its manually annotated, high‐quality closed genome, (ii) re‐analysis of in situ data from the 2009– ...

... Biostimulation is widely used to enhance reductive dechlorination of chlorinated ethenes in contaminated aquifers. However, the knowledge on corresponding biogeochemical responses is limited. In this study, glycerol was injected in an aquifer contaminated with cis‐dichloroethene (cDCE), and geochemical and microbial shifts were followed for 265 days. Consistent with anoxic conditions and sulfate r ...

... For the most‐extreme fungal xerophiles, metabolic activity and cell division typically halts between 0.700 and 0.640 water activity (approximately 70.0–64.0% relative humidity). Here, we investigate whether glycerol can enhance xerophile germination under acute water‐activity regimes, using an experimental system which represents the biophysical limit of Earth's biosphere. Spores from a variety of ...

... There is huge variability among yeasts with regard to their efficiency in utilizing glycerol as the sole source of carbon and energy. Certain species show growth rates with glycerol comparable to those reached with glucose as carbon source; others are virtually unable to utilize glycerol, especially in synthetic medium. Most of our current knowledge regarding glycerol uptake and catabolic pathways ...

... Glycerol is a key compound for the understanding of the microbiology of hypersaline environments. At the highest salt concentrations the main or even sole primary producer is the green unicellular alga Dunaliella, which uses photosynthetically produced glycerol as osmotic stabilizer and compatible solute. Glycerol can be expected to be a major carbon source available to the heterotrophic communiti ...

... Haloarchaea are heterotrophic members of the Archaea that thrive in hypersaline environments, often feeding off the glycerol that is produced as an osmolyte by eucaryotic Dunaliella during primary production. In this study we analyzed glycerol metabolism genes in closed genomes of haloarchaea and examined published data describing the growth properties of haloarchaea and experimental data for the ...

... Glycerol synthesis is key to central metabolism and stress biology in Saccharomyces cerevisiae, yet the cellular adjustments needed to respond and adapt to glycerol stress are little understood. Here, we determined impacts of acute and chronic exposures to glycerol stress in S. cerevisiae. Glycerol stress can result from an increase of glycerol concentration in the medium due to the S. cerevisiae ...

... Sulfide mineral precipitation occurs at mid‐ocean ridge (MOR) spreading centers, both in the form of plume particles and seafloor massive sulfide structures. A common constituent of MOR is the iron‐bearing sulfide mineral pyrrhotite, which was chosen as a substrate for in‐situ incubation studies in shallow waters of Catalina Island, CA to investigate the colonization of iron‐oxidizing bacteria. Mi ...

... Many plant‐associated fungi host endosymbiotic endobacteria with reduced genomes. While endobacteria play important roles in these tri‐partite plant–fungal–endobacterial systems, the active physiology of fungal endobacteria has not been characterized extensively by systems biology approaches. Here, we use integrated proteomics and metabolomics to characterize the relationship between the endobacte ...

... It is well established that resource quantity and elemental stoichiometry play major roles in shaping below and aboveground plant biodiversity, but their importance for shaping microbial diversity in soil remains unclear. Here, we used statistical modeling on a regional database covering 179 locations and six ecosystem types across Scotland to evaluate the roles of total carbon (C), nitrogen (N) a ...

... Laribacter hongkongensis is a fish‐borne pathogen associated with invasive infections and gastroenteritis. Its adaptive mechanisms to oxygen‐limiting conditions in various environmental niches remain unclear. In this study, we compared the transcriptional profiles of L. hongkongensis under aerobic and anaerobic conditions using RNA‐sequencing. Expression of genes involved in arginine metabolism si ...